body {
    font-family: Arial, sans-serif;
    background: #f5f6fa;
    margin: 0;
    padding: 0;
}
header {
    background: #3498db;
    color: #fff;
    padding: 24px 0 12px 0;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
h1 {
    margin: 0;
    font-size: 2.2em;
    letter-spacing: 2px;
}
main {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 40px;
}
ul {
    list-style: none;
    padding: 0;
}
li {
    margin: 18px 0;
}
a {
    display: inline-block;
    padding: 12px 36px;
    background: #3498db;
    color: #fff;
    border-radius: 6px;
    text-decoration: none;
    font-size: 1.1em;
    transition: background 0.2s;
}
a:hover {
    background: #217dbb;
}